Within London, all London Underground, National Rail, London Overground, TfL Rail and Docklands Light Railway stations are assigned to six fare zones. Fare zone 1 covers the central area and fare zones 2, 3, 4, 5 and 6 form concentric rings around it.
Fare zone 6 is an outer zone of Transport for London's zonal fare system used for calculating the price of tickets for travel on the London Underground, London Overground, Docklands Light Railway, National Rail services (since 2007), and the Elizabeth line within Greater London.
A Travelcard gives you unlimited travel within London zones 1-4 or 1-6 on the Underground, Overground, TfL Rail, Docklands Light Railway, buses, trams, and most National Rail services in London*.
Zone 1 covers the West End, the Holborn district, Kensington, Paddington and the City of London, as well as Old Street, Angel, Pimlico, Tower Gateway, Aldgate East, Euston, Vauxhall, Elephant & Castle, Borough, London Bridge, Earl's Court, Marylebone, Edgware Road, Lambeth North and Waterloo.
You can use your Oyster card on all Southern trains within the London Zones 1-6 – as well as on buses, Tubes, Trams, The Docklands Light Railway, London Overground, TfL Rail and most National Rail services in London.
You can use your Oyster card on all Great Northern trains within the London zones 1-6 – as well as on buses, Tubes, Trams, The Docklands Light Railway, London Overground, TfL Rail and most National Rail services in London.
Covent Garden is a London Underground station serving Covent Garden and the surrounding area in the West End of London. It is on the Piccadilly line between Leicester Square and Holborn stations and is in Travelcard Zone 1.
Central London is zone 1, zone 2 is the ring around zone 1, zone 3 is the ring around 2 and so on. If you look at the zone map below it should make sense. *zones 7,8 and 9 cover a small area just outside North West London including Watford, Croxley Green, Rickmansworth, Amersham or Chalfont & Latimer.